1. Field
The present disclosure is directed to a method and apparatus for interpolating pixel colors from color and panchromatic channels to color channels. In particular, the present disclosure is directed to a method and apparatus for interpolating pixel colors from color and panchromatic channels to color channels based on a detected color temperature.
2. Introduction
Presently, people enjoy taking pictures of friends, family, children, vacations, flowers, landscapes, and other scenes using digital cameras. Some cameras now use panchromatic, such as Clear (C), pixels along with chromatic pixels, such as Red, Green, and Blue (RGB) pixels for improved image quality. For example, in a single or multiple camera system, panchromatic pixels may be included to reduce low-light noise, and to increase dynamic range on an output RGB image, because the spectral response of panchromatic pixels is higher than that of chromatic pixels. These result in four channels, such as RGBC channels, of RAW data in input image data, but there are only three channels of RGB or YCbCr data in output image data. An operation of color interpolation is necessary to convert the four channels to three channels, such as the RGB or YCbCr channels.
Different types of light sources provide different color temperatures of scenes. Such different types of light sources include Halogen light, sunlight, fluorescent light, tungsten light, and other types of light sources that produce a color temperature of a scene. This color temperature of a scene affects the color interpolation. However, present approaches do not take the color temperature into account for the color interpolation, which results in a suboptimal final image. Thus, there is a need for a method and apparatus for interpolating pixel colors from color and panchromatic channels to color channels based on a detected color temperature.